The present invention relates to a semiconductor device, which can be used appropriately as, e.g., a semiconductor device including an insulated gate bipolar transistor (IGBT).
As an IGBT having a low ON resistance, a trench-gate-type IGBT has been used widely. There has been developed an IE-type IGBT in which, in a cell formation region, active cell regions each coupled to an emitter electrode and inactive cell regions each including a floating region are alternately arranged to allow an IE (Injection Enhancement) effect to be used. The IE effect reduces the likelihood of discharging of holes from the emitter electrode when the IGBT is in an ON state and thus increases the density of the charges stored in a drift region.
Japanese Unexamined Patent Publication No. 2012-256839 (Patent Document 1) discloses a technique in which, in an IE-type trench-gate IGBT, each of linear unit cell regions provided in a cell formation region includes a linear active cell region and linear inactive cell regions provided on both sides of the linear active cell region such that the linear active cell region is interposed therebetween.
Japanese Unexamined Patent Publication No. 2013-140885 (Patent Document 2) discloses a technique in which, in an IE-type trench-gate IGBT, each of linear unit cell regions provided in a cell formation region includes a linear hybrid cell region and, in the linear hybrid cell region, a first linear hybrid sub-cell region and a second linear hybrid sub-cell region are provided.
Japanese Unexamined Patent Publication No. 2006-210547 (Patent Document 3) discloses a technique in which, in an insulated-gate-type semiconductor device, a second semiconductor layer having a second conductivity type and provided over a first semiconductor layer having a first conductivity type, a plurality of striped trenches formed in a top surface of the second semiconductor layer, and a plurality of third semiconductor regions each having the first conductivity type and formed selectively in a longitudinal direction between the trenches are provided.